I redid all of Falco's quests and this time I was able to deliver the report in time. I guess I fooled around too much the last time and wasted precious time in this timed quest. Serves me right for not paying attention to the time limit in the first place.

The spriggan quest seems to have a time limit also. I played that part 3 different times until I got it. I would recommend to save just before you start this quest and then not until you have killed all that are necessary. In my games I killed the right number of spriggans each time but because I didn't know where they were I lost some time and the journal never triggered. Once I knew where they were I reloaded, killed them off, and my journal updated. Maybe it wasn't the time, but it seems to have been that for me.